Assert that the new room has a predecessor set

tests-e2e/main_test.go

@@ -110,7 +110,7 @@ func MatchRoomRequiredState(events []Event) m.RoomMatcher {
 				}
 			}
 			if !found {
-				return fmt.Errorf("required state want event %+v but it does not exist", want)
+				return fmt.Errorf("required state want event %+v but did not find exact match", want)
 			}
 		}
 		return nil

tests-e2e/tombstone_test.go

@@ -2,11 +2,13 @@ package syncv3_test
 
 import (
 	"encoding/json"
+	"fmt"
 	"testing"
 	"time"
 
 	"github.com/matrix-org/sync-v3/sync3"
 	"github.com/matrix-org/sync-v3/testutils/m"
+	"github.com/tidwall/gjson"
 )
 
 func TestTombstonesFlag(t *testing.T) {
@@ -22,6 +24,9 @@ func TestTombstonesFlag(t *testing.T) {
 				Filters: &sync3.RequestFilters{
 					IsTombstoned: &boolFalse,
 				},
+				RoomSubscription: sync3.RoomSubscription{
+					RequiredState: [][2]string{{"m.room.create", ""}},
+				},
 			},
 		},
 	})
@@ -36,6 +41,7 @@ func TestTombstonesFlag(t *testing.T) {
 		t.Fatalf("failed to decode response: %s", err)
 	}
 	newRoomID := body["replacement_room"].(string)
+	t.Logf("old %s new %s", roomID, newRoomID)
 	time.Sleep(100 * time.Millisecond) // let the proxy process it
 
 	res = client.SlidingSync(t, sync3.Request{
@@ -45,24 +51,47 @@ func TestTombstonesFlag(t *testing.T) {
 			},
 		},
 	}, WithPos(res.Pos))
+	var tombstoneEventID string
 	// count is 1 as we are auto-joined to the upgraded room
 	m.MatchResponse(t, res, m.MatchList(0, m.MatchV3Count(1), m.MatchV3Ops(
 		m.MatchV3DeleteOp(1),
 		m.MatchV3InsertOp(0, newRoomID), // insert new room
 		m.MatchV3DeleteOp(1),            // remove old room
-	)), m.MatchRoomSubscriptionsStrict(map[string][]m.RoomMatcher{
+	)), m.MatchRoomSubscriptions(map[string][]m.RoomMatcher{
 		roomID: {
 			m.MatchRoomInitial(false),
-			MatchRoomTimeline([]Event{
-				{
-					Type:     "m.room.tombstone",
-					StateKey: ptr(""),
-				},
-			}),
+			func(r sync3.Room) error {
+				// last timeline event should be the tombstone
+				lastEvent := r.Timeline[len(r.Timeline)-1]
+				ev := gjson.ParseBytes(lastEvent)
+				if ev.Get("type").Str != "m.room.tombstone" || !ev.Get("state_key").Exists() || ev.Get("state_key").Str != "" {
+					return fmt.Errorf("last event wasn't a tombstone event: %v", string(lastEvent))
+				}
+				tombstoneEventID = ev.Get("event_id").Str
+				return nil
+			},
 		},
+		// 2nd MatchRoomSubscriptions so we can pull out the event ID from the old room
+	}), m.MatchRoomSubscriptions(map[string][]m.RoomMatcher{
 		newRoomID: {
 			m.MatchRoomInitial(true),
 			m.MatchJoinCount(1),
+			func(r sync3.Room) error { // nest it so the previous matcher has time to set tombstoneEventID
+				return MatchRoomRequiredState([]Event{
+					{
+						Type:     "m.room.create",
+						StateKey: ptr(""),
+						Content: map[string]interface{}{
+							"room_version": "9",
+							"predecessor": map[string]interface{}{
+								"room_id":  roomID,
+								"event_id": tombstoneEventID,
+							},
+							"creator": client.UserID,
+						},
+					},
+				})(r)
+			},
 		},
 	}))
 }